Critical windows of disease risk: amphibian pathology driven by developmental changes in host resistance and tolerance
Critical windows of disease risk: amphibian pathology driven by developmental changes in host resistance and tolerance
复制标题
DOI：
10.1111/j.1365-2435.2010.01830.x
复制
发表时间：
2011-06-01
影响因子：
5.2
通讯作者：
Bowerman, Jay
中科院分区：
文献类型：
--
作者：
Johnson, Pieter T. J.;Kellermanns, Esra;Bowerman, Jay
P>1。动物疾病生态学中的一个新兴框架试图将宿主对疾病的反应“分解”为抵抗力（或其在暴露后抵抗感染的能力）和耐受性（或其限制与感染相关的损害的能力）。然而，这些过程在宿主的生命史中如何变化，以及抵抗力和耐受性的发育变化是否解释了疾病脆弱性的“关键窗口”仍然是悬而未决的问题。2．关键的发育窗口对于改变宿主发育的感染尤其重要。最近，对患有严重肢体畸形的两栖动物的观察增多，引发了关于造成这种现象的原因以及是否可以利用畸形类型来推断肇因的争论。例如，吸虫寄生虫 Ribeiroia ondatrae 经常与多腿青蛙的描述有关，但据信对于解释失踪的有腿动物并不重要。在这里，我们测试了宿主发育阶段（从卵到变态后）对太平洋合唱蛙（Pseudacris regilla）暴露于吸虫感染后的死亡风险和畸形类型的影响。3。与脆弱性的关键窗口一致，在前肢和早期肢体发育期间暴露的动物中，宿主死亡率和畸形最高（15-90%），并随着逐渐发育降低至< 5%。早期动物也表现出较高的肢体缺失频率，而额外的肢体和肢体元件主要在肢体发育开始后暴露的蝌蚪中发育。在肢体发育后期感染的宿主是正常的或仅表现出轻微的生长和异常的皮肤蹼。4。宿主耐受性的增加而不是宿主抵抗力的增加在很大程度上解释了观察到的病理学变化。在宿主变态之前，寄生虫在入侵宿主组织方面表现出相当的成功，但所造成的损害程度随着宿主大小和发育阶段的不同而显着不同。然而，变态后的宿主对感染的抵抗力明显增强。5．这些发现强调了传染病关键发育窗口的重要性，并强调了宿主耐受性的发育变化在控制这一过程中的作用。例如，预测的气候变化具有巨大的潜力，可以影响自然界中宿主与寄生虫相互作用的时间和强度。
P>1. An emerging framework in animal disease ecology seeks to 'decompose' a host's response to disease into resistance, or its ability to resist infection following exposure, and tolerance, or its ability to limit the damage associated with infection. How these processes vary over the life history of a host, however, and whether developmental changes in resistance and tolerance account for 'critical windows' of disease vulnerability remain open questions.2. Critical developmental windows are particularly important for infections that alter host development. Recently, increased observations of amphibians with severe limb malformations have stimulated debate over the causes responsible and whether malformation types can be used to infer the agent responsible. The trematode parasite Ribeiroia ondatrae, for example, is often implicated in accounts of extra-legged frogs, but is believed to be unimportant in explaining missing legged animals. Here, we test the influence of host developmental stage, from eggs to post-metamorphosis, on the risk of mortality and the types of malformations produced in Pacific chorus frogs (Pseudacris regilla) following exposure to trematode infection.3. Consistent with a critical window of vulnerability, host mortality and malformations were greatest among animals exposed during pre-limb and early limb development (15-90%) and decreased to < 5% with progressive development. Early stage animals also exhibited a higher frequency of missing limbs, whereas extra limbs and limb elements developed predominantly among tadpoles exposed after limb development was initiated. Hosts infected later in limb development were normal or exhibited only minor outgrowths and abnormal skin webbings.4. Increases in host tolerance rather than host resistance largely explained the observed changes in pathology. Prior to host metamorphosis, parasites exhibited comparable success invading host tissue, but the amount of resulting damage differed significantly as a function of host size and developmental stage. Following metamorphosis hosts were significantly more resistant to infections, however.5. These findings highlight the importance of critical developmental windows for infectious diseases and underscore the role of developmental changes in host tolerance in controlling this process. Forecasted changes in climate, for example, have enormous potential to influence both the timing and intensity of host-parasite interactions in nature.